Single‐atom catalysts have demonstrated interesting activity in a variety of applications. In this study, we prepared single Co2+sites on graphitic carbon nitride (C3N4), which was doped with carbon for enhanced activity in visible‐light CO2reduction. The synthesized materials were characterized with a variety of techniques, including microscopy, X‐ray powder diffraction, UV‐vis spectroscopy, infrared spectroscopy, photoluminescence spectroscopy, and X‐ray absorption spectroscopy. Doping C3N4with carbon was found to have profound effect on the photocatalytic activity of the single Co2+sites. At relatively low levels, carbon doping enhanced the photoresponse of C3N4in the visible region and improved charge separation upon photoactivation, thereby enhancing the photocatalytic activity. High levels of carbon doping were found to be detrimental to the photocatalytic activity of the single Co2+sites by altering the structure of C3N4and generating defect sites responsible for charge recombination.
Heterogeneous In/Mo cooperative bandgap engineering for promoting visible-light-driven CO 2 photoreduction
Improving the low charge separation efficiency, poor light absorption capacity, and insufficient active sites of photocatalysts are the important challenges for CO 2 photoreduction. In this study, a Mo modified InOOH/In(OH) 3 heterojunction with enhanced CO 2 reduction efficiency was synthesized in situ by using an In(OH) 3 monatomic lamellar material with isolated In atom sites exposed on its surface. And bandgap tuning via the energy levels formed by Mo doping and vacancy defect engineering can simultaneously improve visible light absorption and photogenerated charge separation. The results of experimental characterization and DFT calculation show that the Mo impurity energy levels, O defect energy levels, and surface Mo atoms existing in the InOOH phase can act as an electron transfer ladder in cooperation with the In defect energy levels in the In(OH) 3 phase, thereby promoting electron transfer between heterogeneous interfaces. Under visible light irradiation, the evolution rates of CH 4 and CO of the Mo modified InOOH/In(OH) 3 photocatalyst are more than ∼11 and ∼8 times higher than those of InOOH, respectively. This work provides new insights into the design of the CO 2 photoreduction platform through a collaborative strategy of bandgap tuning, transition metal doping, and heterostructure construction.
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- Award ID(s):
- 1945558
- NSF-PAR ID:
- 10401395
- Date Published:
- Journal Name:
- Journal of Materials Chemistry A
- Volume:
- 10
- Issue:
- 25
- ISSN:
- 2050-7488
- Page Range / eLocation ID:
- 13393 to 13401
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D2TA02904A
